Trisodium (4-{[(1S,3R)-1-([1,1′-biphenyl]-4-ylmethyl)-4-ethoxy-3-methyl-4-oxobutyl]amino}-4-oxobutanoate)-(N-pentanoyl-N-{[2′-(1H-tetrazol-1-id-5-yl)[1,1′-biphenyl]-4-yl]methyl}-L-valinate) is approved in USA as octadecasodium hexakis-(4-{[(1S,3R)-1-([1,1′-biphenyl]-4-ylmethyl)-4-ethoxy-3-methyl-4-oxobutyl]amino}-4-oxobutanoate)hexakis-(N-pentanoyl-N-{[2′-(1H-tetrazol-1-id-5-yl)[1,1′-biphenyl]-4-yl]methyl}-L-valinate)penta decahydrate under the brand name of “Entresto” which is represented as below:

The above said compound can also be represented as “Trisodium (4-{[(1S,3R)-1-([1,1′-biphenyl]-4-ylmethyl)-4-ethoxy-3-methyl-4-oxobutyl]amino}-4-oxobutanoate)-(N-pentanoyl-N-{[2′-(1H-tetrazol-1-id-5-yl)[1,1′-biphenyl]-4-yl]methyl}-L-valinate) hemipentahydrate”, commonly known as “Trisodium Sacubitril Valsartan hemipentahydrate.”.
Valsartan/sacubitril (brand name Entresto, previously known as (LCZ696) is a combination drug for use in heart failure developed by Novartis. It consists of the angiotensin receptor blocker valsartan and the neprilysin inhibitor sacubitril, in a 1:1 mixture by molecule count. The combination is sometimes described as an “angiotensin receptor-neprilysin inhibitor” (ARNi). It was approved under the FDA's priority review process on Jul. 7, 2015.
Valsartan/sacubitril is used to treat heart failure in people with reduced left ventricular ejection fraction (LVEF).[3] It is not known whether valsartan/sacubitril is useful for the treatment of heart failure people with normal LVEF.
U.S. Pat. No. 8,877,938B2 disclosed the process for the preparation of Trisodium (4-{[(1S,3R)-1-([1,1′-biphenyl]-4-ylmethyl)-4-ethoxy-3-methyl-4-oxobutyl]amino}-4-oxobutanoate)-(N-pentanoyl-N-{[2′-(1H-tetrazol-1-id-5-yl)[1,1′-biphenyl]-4-yl]methyl}-L-valinate)hemipentahydrate and its crystalline form.
There is a significant need in the art to develop novel polymorphic forms of the said compound of formula-1 which are stable and having advantageous physical properties such as free flowability, greater stability and greater bioavailability.